Air-tankers are fixed wing aircraft used to drop water or fire retardant on fires. More commonly known to the public as Borate Bombers or Water bombers. Until recently a large percentage of the planes have been WW2 era heavy bombers but newer (although still vintage) aircraft are appearing. Most are 2 or 4 engine aircraft but single engine agricultural aircraft are also used, these are known as SEATs (Single Engine Air Tanker). Flying boats and amphibians are popular in areas with many lakes. Most Air Tankers carry 400 to 3000 gallons of fire retardant but there are some that carry much more. Some of the more popular aircraft used in this application have been:
B-17 Flying Fortress, B-25 Mitchell, A-26 Invader, PB4Y2 (Naval B-24), TBM Avenger, PBY Catalina, DC-3, DC-4, DC-6, DC-7, P-2V Neptune, P-3 Orion, S-2 Tracker, C-130 Hercules, CL-215, CL-415, Turbo Thrush and various models of Air Tractor.
There have been some interesting experimental air tankers and limited production aircraft including the Martin Mars, A-10 Warthog, IL-76, DC-10, Boeing 707 and 747.
Lead planes are smaller aircraft used to scout out the path for the larger air tankers. Similar aircraft are used to coordinate the air space over a fire acting as flying air controllers, these are known as Air Attack or Air-Co (Air coordinator). Various surplus military observation aircraft and light civil aircraft have been used in these roles.
Fixed wing aircraft are also used as lookouts patrolling for forest fires much like a lookout tower, and for delivering smoke jumpers. Many types of civil aircraft are used for patrolling but the Ford Tri-motor, DC-3, DHC-6 Twin Otter and C-23 Sherpa have been the primary aircraft used by smoke jumpers in the US.
Helicopters are used for several purposes including water drops using a fixed tank or a suspended bucket, personnel movement, search and rescue, medical evacuation and observation. When used to drop water these aircraft carry 50 to 2000 gallons of water, some may also use foam or fire retardant. An advantage to most helicopters is that they may refill from a water source (pond, river, swimming pool etc) by hovering over it and dipping their bucket or draft hose into it. They also are more precise than fixed wing aircraft allowing them to work in close proximity to ground crews. Like the air tankers many helicopters are military surplus. Some areas call helicopters with tanks holding 1000 gallons or more Heli-tankers. Some of the more common helicopters used are:
Allouette III, Bell 204 (UH-1), Bell 205 (UH-1), Bell 206 Jet ranger, Bell 206-L Long ranger, Bell 212 (UH-1), Bell 214, Bell 407, Bell 412, CH-46 Sea Knight, CH-47 Chinook, CH-53 Jolly Green Giant, CH-54 Sky-crane, Sikorsky S-58 (UH-34), Sikorsky S-61 Sea King and the UH-60 Black Hawk.